This invention relates to a disc brake and more particularly, to an improved disc brake which has a relatively light weight and a high vibration resistance and which is especially suitable for a large size truck and the like.
As is apparent to those skilled in the art, the conventional disc brakes can be generally classified into (1) the opposing piston-type disc brake in which two pistons are disposed on the opposite sides of a disc to brake the disc by the action of the two pistons and (2) the stationary-type disc brake in which a single piston is disposed on only one side of the disc and the piston is operated to apply one friction pad directly against the one side of the disc to generate a reaction force which in turn applies the other friction pad secured to the housing against the other side of the disc.
In the opposing piston-type disc brake, since the hydraulically operated pistons are disposed on the opposite sides of the disc, the braking is direct and positive, but the disc brake has the disadvantages that at the time of braking, there is great possibility for occurrence of the so-called vapor lock due to frictional heat and that the overall device has a large size. On the other hand, although the stationary-type disc brake can be constructed in a relatively small size and the amount of pedal movement can be made small, this type of disc brake inevitably increases the size of the housing and brings about many problems relating to vibration resistance.